AIM To analyze the origin of the anticipationphenomenon,which means earlier death insuccessive generation in familial adenomatouspolyposis.METHODS The study subjects were 2161patients with familial adenomatous polypos...AIM To analyze the origin of the anticipationphenomenon,which means earlier death insuccessive generation in familial adenomatouspolyposis.METHODS The study subjects were 2161patients with familial adenomatous polyposisand their 7465 first-degree relatives who weremembers of 750 families registered at ourPolyposis Registry.The ages at death andcumulative mortality rates in the parent,theproband,and the child generations werecompared for both all subjects and the patientsalone.RESULTS In the patients over 5 years of age,the mean age at death was 50.9 years for theparent,42.3 years for the proband,and 33.3years for the child generations,respectively(P【0.001).The deceased rates in the threegenerations were 90.7%,51.3% and 23.1% ofthe patients,respectively,and this differencewas the main cause of the anticipation measuredby parent-child paring method.The cumulativemortality rates for all subjects failed to showanticipation,however the cumulative mortalityrates for the patients showed the anticipation.The anticipation phenomenon was shown by anyparent-child pairing methods for the deceasedpatients.Other important causes of theanticipation were different proportion of causesof death between generations(P【0.001),and alow proportion of detected or deceased patients (P【0.001)in the child generation.CONCLUSION Anticipation in familialadenomatous polyposis may be caused byparent-child paring methods as well as severalintergenerational biases.展开更多
Objective:To identify the causative adenomatous polyposis coli(APC)gene defects associated with a pedigree of familial adenomatous polyposis(FAP).Methods:FAP was diagnosed based on clinical manifestations,family histo...Objective:To identify the causative adenomatous polyposis coli(APC)gene defects associated with a pedigree of familial adenomatous polyposis(FAP).Methods:FAP was diagnosed based on clinical manifestations,family history,as well as endoscopic and pathological examinations.The blood samples of the FAP pedigree members,colonic polyp patients,and normal individuals were collected.Genomic DNA was then extracted from those samples.APC mutation analysis was conducted via direct polymerase chain reaction(PCR)sequencing.Results:Three synonymous mutations and a missense mutation were found:c.5034G>A(p.Glyl678Gly),c.5465T>A(p.Vall 822Asp),c.5880G>A(p.Prol960Pro),and c.5274T>G(p.Serl758Ser)・Among them,the homozygous mutation on APC gene c.5034G>A has been reported,while the other three mutations have not been reported in the Chinese Han population.Individuals with c.5465T>A(p.Vall822ASP)missense mutation eventually suffer from colon cancer and have poor prognosis.We found no mutation in patients with simple intestinal polyp and in normal individuals.In addition,there were homozygous and heterozygous mutations in different patients from the same family.Conclusion:Three new mutations of APC gene were firstly reported in Han population.The missense mutation of c.5465T>A(p.Vall 822Asp)may be the cause of carcinogenesis in this FAP pedigree with poor prognosis.展开更多
Colorectal cancer (CRC) is the second cause of cancer deaths, with over 1 million new cases estimated every year. Familial adenomatous polyposis, MUTYH-associated polyposis and hamartomatous polyposis are inherited sy...Colorectal cancer (CRC) is the second cause of cancer deaths, with over 1 million new cases estimated every year. Familial adenomatous polyposis, MUTYH-associated polyposis and hamartomatous polyposis are inherited syndromes that account for 2%-5% of all colon cancer. The mutated genes responsible for the vast majority of these disorders, are now known (MLH1, MSH2, MSH6, PMS2, APC, MYH, LKB1, SMAD4, BMPR1A, and PTEN) and specific mutations have been identified. Molecular caracterization of inherited CRCs allows pre-symptomatic diagnosis identifying at-risk individuals and improving cancer surveillance. Adenomatous polyposis includes familial adenomatous polyposis (FAP), attenuated FAP (AFAP), and MUTYH-associated polyposis (MAP). Hamartomatous polyposis comprises Peutz-Jeghers syndrome (PJS), juvenile polyposis syndrome (JPS) and “PTEN hamartoma tumour syndrome” (PHTS). MAP is an autosomal recessive condition, while all other disorders are inherited in an autosomal dominant manner. Differential dyagnosis could be very difficult between syndromes because of their phenotypic variability. Attenuated FAP, MAP and Lynch syndrome could be all associated with fewer numbers of adenomas (3-10 polyps), nevertheless, each syndrome has distinct cancer risks, characteristic clinical features, and separate genetic etiologies. Thus, differential diagnosis is essential for correct management of the specific disease. In our laboratory we set up a methodology for genetic tests of the colorectal polyposis syndrome. In these reviews we summarize the literature data and our experience about diagnosis, genetic tests and cancer risk assesment associated with colorectal polyposis. According to literature data, in our experience, there is a portion of analyzing patients that remain without identified mutation, after molecular screening of the specific gene involved in the pathogenesis of the disease. Since the sensibility of used techniques, such as DHPLC, MLPA and sequencing, is now very high, we suggest that a different approach to molecular diagnosis of polyposis syndromes is necessary. In our laboratory, we are now planning to set up analysis of a larger pannel of genes that could be involved in colorectal poliposis syndromes, using a next generation sequencing techniques. In our opinion, a better characterization of molecular basis of the polyposis syndromes will allow a more efficient cancer prevention.展开更多
基金Foundation for Promotion of Cancer Research in JapanGrant in Aid from the Ministry of Health and WelfareJapanese Society for Cancer of the Colon and Rectum
文摘AIM To analyze the origin of the anticipationphenomenon,which means earlier death insuccessive generation in familial adenomatouspolyposis.METHODS The study subjects were 2161patients with familial adenomatous polyposisand their 7465 first-degree relatives who weremembers of 750 families registered at ourPolyposis Registry.The ages at death andcumulative mortality rates in the parent,theproband,and the child generations werecompared for both all subjects and the patientsalone.RESULTS In the patients over 5 years of age,the mean age at death was 50.9 years for theparent,42.3 years for the proband,and 33.3years for the child generations,respectively(P【0.001).The deceased rates in the threegenerations were 90.7%,51.3% and 23.1% ofthe patients,respectively,and this differencewas the main cause of the anticipation measuredby parent-child paring method.The cumulativemortality rates for all subjects failed to showanticipation,however the cumulative mortalityrates for the patients showed the anticipation.The anticipation phenomenon was shown by anyparent-child pairing methods for the deceasedpatients.Other important causes of theanticipation were different proportion of causesof death between generations(P【0.001),and alow proportion of detected or deceased patients (P【0.001)in the child generation.CONCLUSION Anticipation in familialadenomatous polyposis may be caused byparent-child paring methods as well as severalintergenerational biases.
文摘Objective:To identify the causative adenomatous polyposis coli(APC)gene defects associated with a pedigree of familial adenomatous polyposis(FAP).Methods:FAP was diagnosed based on clinical manifestations,family history,as well as endoscopic and pathological examinations.The blood samples of the FAP pedigree members,colonic polyp patients,and normal individuals were collected.Genomic DNA was then extracted from those samples.APC mutation analysis was conducted via direct polymerase chain reaction(PCR)sequencing.Results:Three synonymous mutations and a missense mutation were found:c.5034G>A(p.Glyl678Gly),c.5465T>A(p.Vall 822Asp),c.5880G>A(p.Prol960Pro),and c.5274T>G(p.Serl758Ser)・Among them,the homozygous mutation on APC gene c.5034G>A has been reported,while the other three mutations have not been reported in the Chinese Han population.Individuals with c.5465T>A(p.Vall822ASP)missense mutation eventually suffer from colon cancer and have poor prognosis.We found no mutation in patients with simple intestinal polyp and in normal individuals.In addition,there were homozygous and heterozygous mutations in different patients from the same family.Conclusion:Three new mutations of APC gene were firstly reported in Han population.The missense mutation of c.5465T>A(p.Vall 822Asp)may be the cause of carcinogenesis in this FAP pedigree with poor prognosis.
文摘Colorectal cancer (CRC) is the second cause of cancer deaths, with over 1 million new cases estimated every year. Familial adenomatous polyposis, MUTYH-associated polyposis and hamartomatous polyposis are inherited syndromes that account for 2%-5% of all colon cancer. The mutated genes responsible for the vast majority of these disorders, are now known (MLH1, MSH2, MSH6, PMS2, APC, MYH, LKB1, SMAD4, BMPR1A, and PTEN) and specific mutations have been identified. Molecular caracterization of inherited CRCs allows pre-symptomatic diagnosis identifying at-risk individuals and improving cancer surveillance. Adenomatous polyposis includes familial adenomatous polyposis (FAP), attenuated FAP (AFAP), and MUTYH-associated polyposis (MAP). Hamartomatous polyposis comprises Peutz-Jeghers syndrome (PJS), juvenile polyposis syndrome (JPS) and “PTEN hamartoma tumour syndrome” (PHTS). MAP is an autosomal recessive condition, while all other disorders are inherited in an autosomal dominant manner. Differential dyagnosis could be very difficult between syndromes because of their phenotypic variability. Attenuated FAP, MAP and Lynch syndrome could be all associated with fewer numbers of adenomas (3-10 polyps), nevertheless, each syndrome has distinct cancer risks, characteristic clinical features, and separate genetic etiologies. Thus, differential diagnosis is essential for correct management of the specific disease. In our laboratory we set up a methodology for genetic tests of the colorectal polyposis syndrome. In these reviews we summarize the literature data and our experience about diagnosis, genetic tests and cancer risk assesment associated with colorectal polyposis. According to literature data, in our experience, there is a portion of analyzing patients that remain without identified mutation, after molecular screening of the specific gene involved in the pathogenesis of the disease. Since the sensibility of used techniques, such as DHPLC, MLPA and sequencing, is now very high, we suggest that a different approach to molecular diagnosis of polyposis syndromes is necessary. In our laboratory, we are now planning to set up analysis of a larger pannel of genes that could be involved in colorectal poliposis syndromes, using a next generation sequencing techniques. In our opinion, a better characterization of molecular basis of the polyposis syndromes will allow a more efficient cancer prevention.
